A laminated glass including two glass plates integrated through an interlayer film for a laminated glass containing plasticized polyvinyl butyral is widely used, particularly, for vehicle windshields.
In the process for producing a laminated glass, deaeration properties upon stacking a glass plate and an interlayer film for a laminated glass on top of each other is important. The interlayer film for a laminated glass therefore commonly has a large number of recesses formed on at least one surface for the purpose of ensuring the deaeration properties in production of a laminated glass. In particular, when the recesses each have a groove shape with a continuous bottom and such recesses in the shape of engraved lines are regularly adjacent and parallel to each other, excellent deaeration properties can be exhibited.
In a method for producing a laminated glass, for example, an interlayer film for a laminated glass unwound from a rolled body is cut into an appropriate size, and the resulting interlayer film for a laminated glass is sandwiched between at least two glass plates. The obtained laminate is placed in a rubber bag and vacuum suctioned so that the glass plates and the interlayer film are preliminarily pressure bonded while air remaining therebetween is removed. Then, the laminate is pressurized with heat, for example, in an autoclave for final pressure bonding (e.g., Patent Literature 1).
In such a method for producing a laminated glass, interlayer films for a laminated glass cut into a predetermined shape in advance are stacked and stored in a constant temperature and humidity room for efficient production. However, the stacked interlayer films for a laminated glass adhere to each other (autohesion) during storage and, disadvantageously, cannot be peeled by a machine transporting interlayer films for a laminated glass or by human power.